'I will rape you' post put on Facebook to advertise Instagram

Instagram used a user-generated image which included the text "I will rape you before I kill you, you filthy whore!" to advertise on parent company, Facebook, the latest sign that Facebook's algorithm needs tweaking.

Guardian reporter Olivia Solon tweeted a picture of the offensive ad, noting that it was one of her "most 'engaging' posts." According to the Guardian, which first reported the story, Solon posted the screenshot nearly a year ago. Instagram selected the post, using it to her advertise to her sister, adding the caption “See Olivia Solon’s photo and posts from friends on Instagram”.

“We are sorry this happened -- it’s not the experience we want someone to have," an Instagram spokesperson told Fox News. "This type of notification is intended to let someone on Facebook know what their friends are up to on Instagram. Posts are generally received by a small percentage of a person’s Facebook friends. We are working to make sure that this doesn’t happen again.”

Earlier this week, Facebook COO Sheryl Sandberg said the company would be revamping its ad-targeting policies after the company received notification from Pro Publica that it was able to purchase ads targeting anti-Semitic categories.

"First, we're clarifying our advertising policies and tightening our enforcement processes to ensure that content that goes against our community standards cannot be used to target ads," Sandberg wrote in a post on her Facebook account. "This includes anything that directly attacks people based on their race, ethnicity, national origin, religious affiliation, sexual orientation, sex, gender or gender identity, or disabilities or diseases. Such targeting has always been in violation of our policies and we are taking more steps to enforce that now."

The tech exec also said the company would be adding more human review and oversight to a process that is largely automated.

Lastly, Facebook will create a program "to encourage people on Facebook to report potential abuses of our ads system to us directly."

"We hope these changes will prevent abuses like this going forward," Sandberg continued. "If we discover unintended consequences in the future, we will be unrelenting in identifying and fixing them as quickly as possible. We have long had a firm policy against hate on Facebook. Our community deserves to have us enforce this policy with deep caution and care."

Earlier this month, ProPublica said it paid Facebook $30 to display three "promoted posts" in the news feeds of people who expressed interest in topics like "Jew hater," "How to burn jews," or, "History of 'why jews ruin the world.'"

ProPublica found that the ads were approved by Facebook in 15 minutes. The categories have since been removed.

Fox News' Chris Ciaccia contributed to this report. This story has been updated to include Instagram's comment.